A green future for cruise liners?

By Lauren Razavi

Work is underway on a prototype environmentally-friendly cruise ship that combines the durability of traditional materials with renewable energy technology

Whether holidaymakers enjoy relaxing on poolside deck chairs or exploring tropical islands, luxury getaways on ocean cruises are growing in popularity. Over the last 10 years, demand for cruises has risen by 68%, and it was estimated that in 2016, over 220 cruise liners carried 24 million passengers on voyages crossing the world.

Cruising may be popular, but it’s not good for the environment. To take those 24 million vacationers across the oceans these boats have to be enormous. Some are even larger than aircraft carriers and can burn through tonnes of diesel every hour. On average, a typical ocean liner uses 225 tonnes of fuel each day, which results in a huge amount of carbon emissions being released.

A single, large vessel produces as much carbon dioxide as 83,678 cars, and as much sulphur dioxide as 376 million cars. Emissions cause havoc for the environment, with carbon dioxide being the major gas contributing to the greenhouse effect, and sulphur dioxide being a key component of acid rain. This rainwater can make bodies of water so corrosive that entire ecosystems become uninhabitable for sea creatures and vegetation. Fortunately, growing awareness of these issues is calling people into action.

Peace Boat is a Japanese non-profit organisation working to promote sustainable development. They run 80-100-day educational voyages that sail participants all around the world while spreading awareness of how ecosystems function and how to take better care of the environment. However, they view their current mode of transport as part of the problem they’re trying to tackle.

“Unfortunately, the boat we use is just a conventional boat, so it’s not the best for the environment,” explains Yoshioka Tatsuya, founder and director of Peace Boat. “I thought it was our responsibility to try to do something about that, and the Ecoship is our answer.”

Peace Boat’s project, Ecoship, is a cruise liner with an environmentally friendly twist. The ship’s design was finalised after three years of in-depth research and development by a global team of engineers and designers. The team took inspiration from the shape of whales to design a ship hull that was more hydrodynamic. This, alongside the ship’s 10 retractable sails, 10 retractable wind turbines and 12,000 square metres of solar panels (almost the area of two football pitches) drastically reduces the volume of fuel needed to propel the ship.

“About 95% of structural weight will be made of steel. It’s the most suitable material for ships because of its low cost and high strength to weight ratio”

Creating a sustainable vessel isn’t just about cutting propulsion energy and electricity; waste management is crucial. A closed-loop water use system will ensure that waste water is reused, purified and re-purposed for a number of things, not least for irrigating the onboard garden, which will be also be fed with organic waste. The Ecoship will therefore have zero water discharge and no sea dumping.

The ship also needs to be strong and durable, so it can sail for a long time. The sea water environment is an aggressive one. The salt in the water, as well as the rising amount of sulphur dioxide, can easily corrode most metals. To ensure the ship doesn’t disintegrate after a few trips, engineers use steel.

“All of the resistant structure will be made of steel,” explains Andrés Molina, project manager for the Ecoship. “About 95% of structural weight will be made of steel. It’s the most suitable material for ships because of its low cost and high strength to weight ratio. It also helps that it isn’t easily corroded by salt water.”

At the moment, Peace Boat is only building one Ecoship, and it’s due to set sail in 2020. If it proves a success, they aim to build four more ships by 2030 to meet market demand. Peace Boat’s ships could transform the construction of all future seafaring vessels, with a view to reducing fuel consumption and limiting the negative impacts that our travels and leisure time have on the planet’s oceans.